[leetcode] 3. Longest Substring Without Repeating Characters (Typescript)

Given a string s, find the length of the longest substring without repeating characters

Example 1:

Input: s = "abcabcbb"

Output: 3

Explanation: The answer is "abc", with the length of 3.

 

Example 2:

Input: s = "bbbbb"

Output: 1

Explanation: The answer is "b", with the length of 1.

 

Example 3:

Input: s = "pwwkew"

Output: 3

Explanation: The answer is "wke", with the length of 3. Notice that the answer must be a substring, "pwke" is a subsequence and not a substring.

 

Example 4:

Input: s = ""

Output: 0

 

Constraints:

• 0 <= s.length <= 5 * 104
• s consists of English letters, digits, symbols and spaces.

 

function lengthOfLongestSubstring(s: string): number {
    let left = 0;
    let right = 0;
    let set = new Set();
    let result = 0;
    
    while (right < s.length) {
        if (set.has(s.charAt(right))) {
            set.delete(s.charAt(left));
            left++;
        } else {
            set.add(s.charAt(right));
            result = Math.max(result, set.size);
            right++;
        }
    }
    
    return result;
};